The Association between Cognitive Impairment and Body Composition among the Elderly: Birjand Longitudinal Aging Study

Abstract

Background: The population of older adults has been steadily increasing around the world. We aimed to assess the possible relationship between cognitive decline and anthropometric indices in older adults, using data from the Birjand longitudinal aging study (BLAS). Methods: In this cross-sectional research, the association between cognitive impairment (Six Item Cognitive Impairment Test (6-CIT)) and (Mini-Mental State Examination (MMSE)) and body composition indices including waist circumference (WC), body mass index (BMI), waist to height ratio (WHtR), waist to hip ratio (WHR), body roundness index (BRI) and a body shape index (ABSI) were assessed among 1353 elderly ≥ 60 years old, participating in the BLAS cohort study (September 2018 to April 2019). Ordinal and binary logistic regression were used for analysis. Results: According to the MMSE test, 58.3% of participants had cognitive impairment while this frequency was 64.2% based on 6-CIT test. A significant reverse association was observed between cognitive decline according to 6-CIT test and BMI, WHR and, WC (P<0.05). Cognitive impairment according to MMSE was inversely associated with WC and directly associated with WHtR and ABSI in the crude model, which disappeared after adjustment for confounders. BRI was not significantly related to any of the cognitive tests. According to BMI and WC, overweight and obesity could reduce the risk of cognitive impairment. Conclusions: Overall, the result of this study showed that the risk of cognitive decline reduced among the elderly as BMI, WC, and WHR increased.